My Production shareing experience

mikesand · Post by **mikesand** » Tue, Aug 14 2007, 11:03AM

Hello all,

I had my first Ecab job cut on a Production sharing member's machine last weekend. I have debated weather or not I should send this as an email to Thremwood or post this here. I think it is important that I share this with everyone. Plus I hope to get feedback from more experienced users out there as well.

Background on me, I took the Ecab class a year ago and have been relying on the soft ware to produce all cut list and shop drawings. I think that I am pretty good with the program and seldom have an issue getting it to do what I want. I have read Ken Susnjara's book and I am a believer in what he is trying to do. I think that it will work if Thermwood keeps the effort up.

This job nested on my computer at 32 sheets of material and there was a fair amount of PE cuts, mostly radius's. So it was the perfect candidate for me to use the production sharing network. It saved me at least a week of shop time to have it cut on the CNC.

I had the job cut Wood Graphics in Lubbock Texas. Grady, the proprietor, worked very hard to make sure that the job was done to my satisfaction. He went through a lot of trouble to cut this job for me, including buying new tooling and bringing in technical help for cutting dovetails, and working a 12 hour day on a Saturday. I will definitely work with him again.

The biggest issue, and it cost us at least 4 hours, was that there are parameters that must be set in the designers file before the CNC gets it. But there is no way for the designer to know these parameters before hand, and the CNC operator is stuck having to deal with it. Unfortunately there seems to be no easy way to make these changes at the machine. Material thickness was the biggest issue. If the material is drop shipped to the CNC I have no way to set the proper thickness in the file. On the dovetail drawers there are some settings that refer to the tooling parameters, including the fit clearance. I could not possibly know these settings. In fact the machine operator will not know the clearance values until a test drawer is cut.

This wouldn't be that big of an issue except that changing these values in the .esj, then creating the CNC file, then nesting that file at the machine can easily take an hour.

Here is an example; If you use under mount drawer slides, Blum Tandem for example, the drawer width is dictated by the material thickness. Because of this and the tooling parameters I had to open each cabinet change the drawer left and right inset values in the Construction Parameters. Then I had to go into the Drawer/ Door Area and delete each drawer and add them again the make the changes take. This job had 22 drawers, so it took over an hour to do this. I also had to go into every cabinet and change the materials out so the thickness was correct. Using the change sheet stock command in the custom layout area doesn't work. It randomly skips parts, even simple parts that have no PE cuts, and it takes a long time to process a large job. So after waiting for 15 to 30 minutes for the job to rebuild you see that there are still lots of random unchanged parts in the cabinets and it is still necessary to edit each cabinet any way. Rebuilding the dovetailed drawers takes even longer. So after making a test cut there was a hour long process to rebuild the file and remake the CNC file. This was done several times. Like I said, the CNC operator was very patient and worked hard to get all this done.

It is a very fortunate thing that I bought the material before hand and drove the 300+ miles to Grady's shop. If I had drop shipped the material and emailed the file I don't think there is any way the job could have come out right. I don't think that the CNC operator wants the responsibility of making all those changes to the job and risking deviating from the design. Not to mention the time involved. But once the CNC file is created there seems to be no way of making these changes without starting over. I understand that most of these issues are minimised when using MDF or Melamine because the stock is uniformly manufactured. But MDF cabinets are not an option for me.

I can see a few solutions to this problem, but they all require a lot of work by the Thermwood team. It seems that after spending so much time developing Ecabinets the machine interface has fallen behind (I was not the only one to reach this conclusion).

All in all, the Ecabinets coopertave concept did work for me. I has able to go from 35 sheets of uncut material into 21 assembled cabinet boxes in two days. For a two man shop that is unreal, especially considering the curves and radiused parts that would have required special jigs to cut out. My real concern is for the CNC operator. If production sharing is too problematic they will either have to increase their rates to compensate for the front end time spent, or they will decide it is not worth it. Either way the result is fewer jobs cut on a Thermwood router, and that is ultimately the goal of the Ecabinet/Thermwood cooperative.

Hope this helps others, I also would like to hear what other production sharing partners are doing to make this process easier.

Thanks,
Mike

mikesand · Post by **mikesand** » Tue, Aug 14 2007, 11:07AM

My post was cut short here is the rest

It is a very fortunate thing that I bought the material before hand and drove the 300+ miles to Grady's shop. If I had drop shiped the material and emailed the file I don't think there is any way the job could have come out right. I don't think that the CNC operator wants the responsibility of making all those changes to the job and risking deviating from the design. Not to mention the time involved. But once the CNC file is created there seems to be no way of making these changes without starting over. I undestand that most of these issues are minimised when using MDF or Melamine because the stock is uniformly manufactured. But MDF cabinets are not an option for me.

I can see a few solutions to this problem, but they all require a lot of work by the Thermwood team. It seems that after spending so much time developing Ecabinets the machine interface has fallen behind (I was not the only one to reach this conclusion).

All in all, the Ecabinets coopertave concept did work for me. I has able to go from 35 sheets of uncut material into 21 assembled cabinet boxes in two days. For a two man shop that is unreal, especially considering the curves and radiused parts that would have required special jigs to cut out. My real concern is for the CNC operator. If production shareing is too problematic they will either have to increase their rates to compensate for the front end time spent, or they will decide it is not worth it. Either way the result is fewer jobs cut on a Thermwood router, and that is ultimately the goal of the Ecabinet/Thermwood cooperative.

Hope this helps others, I also would like to hear what other production shareing partners are doing to make this process easier.

Thanks,
Mike

Forrest Chapman · Post by **Forrest Chapman** » Tue, Aug 14 2007, 1:27PM

Hi Mike,

I have 2 kinds of customers. Those that come to me for advise before completing designs and those that ask after. I can tell you that any shop who machines parts and has real world experiance would prefer to spend time before hand helping to eleminate potential problems. This usually means also looking through the job file to get familier with each shops techniques and making suggestions based on what is seen. That being said I'm glad that Grady was diligent in working through these issues with you and I believe that your experience will make your designs stronger and more unique.

Forrest

Post by **Jason Susnjara** » Tue, Aug 14 2007, 1:27PM

Hi Mike,

The way that this should work (everyone will be different) is a member should send the esj file to the production sharing member. Then the production sharing member will need to figure out what the average material thickness is using your material. This can then be changed when creating the cnc file. For example the image below shows that I have changed the .75 material to .72 and I also changed the thickness for the drawer box material. After this change takes place (automatically), the twd file is created and will be cut at the machine. We have talked about putting this control in the machine but requires a lot of work plus some more license fees that are associated. This has to happen when cutting jobs not related to production sharing. All of the carcasses that we have cut here for our office has to go through changing the material thickness when creating the twd file.

Some members send just the twd file which works sometimes but in the long run they will have problems with material thickness changes. Because material thickness changes frequently and not the same each time it is easier to create the initial sheet stock at the defined thickness (.75, .5, .25, etc..) then to create a material for each and every thickness that you might run across for .75 thick.

Hope this makes sense and that I answered your question. If not please explain further.

thanks,

mikesand · Post by **mikesand** » Tue, Aug 14 2007, 1:44PM

Thanks Jason,

We did that and most of the part editor cuts dropped out and the drawer boxes had to be resized (the side inset values for the cabinets), and what do you sujest for the dovetail tooling issues?

And so I understand, all I should do is design with generic thicknesses (.75, .5, .375, etc) and then leave the rest up to the machine shop? When the TWD file is created it will rebuild the job with the new values? Does Ecabs use the same routine for changing material thickness when generating the TWD file as it does when changing the material in the \"change sheet stock\" function.

Thanks for the help,

Mike

mikesand · Post by **mikesand** » Tue, Aug 14 2007, 1:50PM

Forrest,

I sent the file before we started, just barely, and the file looked good as far as construction details and clearence values. I am definately glad that I went to the shop (even though it was a 5 hour drive each way) to get this job done. I see now some of the issues that I have to watch out for.

I agree that the first job should be done togather.

Mike

Post by **Jason Susnjara** » Tue, Aug 14 2007, 2:26PM

Hi Mike,

When you change the material thickness for a drawer box, the overall size of the box will stay the same, only the inside of the box will change dimensions. The inset values that you use for the right and left sides to accomodate the slides should stay the same.

The part editor cuts getting lost when changing material thickness needs to be brought to the programmers attention so that they can fix this problem.

The dovetail tooling is controlled at the machine other than some tolerances that need to be set in eCabinets. Ususally if production sharing members have cut dovetail drawer boxes then they might have a list of set tolerances that they would like for you to use when creating the job.

Yes and no. This all depends on the production sharing member. Most of the members if not all of them usually will take your esj file and then convert it to twd file so that they can change the material thickness for the job as they have the material. This might be different when machining MDF and Melamine as you said before.

Yes, the same goes for changing the material thickness within eCabinets (room layout, batch) as it does when creating the twd file.

On a different note, depending on what construction method you are using, there are different tolerances that need to be set and usually having the production sharing member giving you insight to this is what generally happens. Therefore when you create your next job, it will go a lot smoother than the first one.

Let me know if I am wrong Forrest as I am not in Production Sharing.

thanks,

Brian Shannon · Post by **Brian Shannon** » Tue, Aug 14 2007, 2:40PM

Jason,

What Mike is saying about Dovetail Box sizing is correct. Undermount slide clearances are from the openning to the INSIDE of the drawer box. If using 12mm Baltic ply, the boxes will not work properly unless they are made slightly smaller. If the designer knows they are using 12mm material, they just have to change their library base to reflect the side inset difference. Hope this clears things up about the drawers.

Brian

Forrest Chapman · Post by **Forrest Chapman** » Tue, Aug 14 2007, 4:55PM

Jason,
This is true, most cnc shops will either give a drawer box or all the settings nessesary to create a good fit.

Most of the time (we) don't obsess over measuring thickness every time because plywood will vary in the same sheet. The safest and fastest method is find a good average and stick with it. This is something the cnc shop can help with.

Brian,
I don't know what materials are being used but baltic birch is one of the more consistant thickness wise and should be able to set up with an accurate and stable measurement. I also use a maple fibercore material that is custom laid up which makes fantastic looking drawer boxes and is always the same thickness.

Hope this helps,
Forrest

mikesand · Post by **mikesand** » Wed, Aug 15 2007, 1:32PM

Forrest,

What is the \"fiber core material\" that you are using? Do you have the trade name, and is it MDF? And of course..... what does it cost?

Thanks,
Mike

Forrest Chapman · Post by **Forrest Chapman** » Wed, Aug 15 2007, 2:29PM

Mike,

The material is 5/8\" maple vaneer 2 side on an mdf core. Cost is around 37.00 per 4x8 sheet. I've had it laid up from Columbia Forest and Murphy Plywood.

Forrest

mikesand · Post by **mikesand** » Thu, Aug 16 2007, 12:01PM

Do you worry about water damage, MDF is very susceptable and even wet hands and splashes from not-quite-dry items could cause issues after some time. Is it something that you offer on builders grade cabinets as a cost saving measure?

Thanks,
Mike

Forrest Chapman · Post by **Forrest Chapman** » Thu, Aug 16 2007, 1:30PM

Mike,

The only place the mdf is exposed is on the dovetail edges and with a good clear coat I don't have any issues with water or anything else.

I put these in any cabinet the customer doesn't actually care if the drawer is solid wood or not(which is most everyone).

Forrest

mikesand · Post by **mikesand** » Fri, Aug 17 2007, 12:54PM

How about the top edge, do you band it? I am not against man-made materials, but I am hesitant to use this stuff on drawers. If it holds up I think I would like it.

Mike

Forrest Chapman · Post by **Forrest Chapman** » Fri, Aug 17 2007, 8:05PM

Yes Mike I band all top edges as I stated before the only place you see the core is on the ends and it looks really nice with just a little contrast.

Forrest